Figure 4. As₂O₃ triggers EndMT in human aortic endothelial cells (HAECs).

(a) Morphological changes of endothelial cells exposed to different concentrations of As₂O₃. (b) Morphological changes of endothelial cells treated with As₂O₃ (2 μmol/l) for 0, 24, 48 or 72 hours. (c) Western blotting results for relative protein levels of VE-cad, CD31, α-SMA and FSP1 in As₂O₃-treated HAECs. GAPDH was used as an internal control. (d) Relative expression levels of endothelial markers (VE-cad, CD31) and mesenchymal markers (α-SMA, FSP1, FN and Vimentin) were compared by qRT-PCR between control groups and As₂O₃-treated groups. FN, fibronectin. (e) Relative mRNA levels of fibrosis-related genes Col1a, Col3a, mmp2 and mmp9. (f) Representative confocal microscopy images showing staining of endothelial marker CD31 and mesenchymal marker α-SMA in As₂O₃-treated HAECs. Scale bar = 30 μm. *p < 0.05, **p < 0.01 vs. untreated condition (0 μmol/l As₂O₃). No significant difference was observed between the different concentrations groups. Data are represented as mean ± SEM, n = 3–5.